One step in the convoluted and unpredictable process of creation is considering why one artistic form is better suited to a given message than another. Why is this particular story being told as a film, as a novel, in a painting — what does this medium bring to it than no other medium can?

I pondered this when watching “Independence Eve,” an hour-long opera about race in America, which UrbanArias presented at the Signature Theatre on Sunday afternoon. The three vignettes between a black man and a white man, set at different times in our history — the past, the present and the future, each at 50-year intervals — are pithy and often uncomfortable, and attempt to be realistic in a way that adding music could be seen to complicate (since black porters and white policemen were not in the habit of singing to each other in public parks during the Kennedy administration).

In this particular case, the music was a mitigating factor: It provided a reassuring propulsive force through situations that were challenging and sometimes hard to watch — such as a young black man’s realization that his well-meaning white friend simply doesn’t get some basic things about racism, when he suggests that maybe he needs to see a shrink to get over his upset at being strip-searched in his apartment lobby.

Too, structuring the piece as an opera, with a musical shape, offers the hopeful illusion of a neat ending, imposing order on a fraught and messy topic.

There’s a lot packed into this small, punchy piece, which takes its singers backward in age — in the last scene, they play 10-year-old boys — even as it moves us all forward in time (the last scene is set in 2063, in a future when the white kid is implied to be the disadvantaged minority). Daniel Neer, the librettist, can be commended for writing text that mostly manages not to be fatuous about subjects that are tricky to condense meaningfully, even when flirting with cliched situations (the 1963 faceoff between the affable porter and the edgy policeman smacks of familiar story lines).

And Sidney Marquez Boquiren’s score is similarly distinctive without being overly maudlin, with strong, clear musical lines for its five-piece chamber orchestra, moving from jagged emotional tension to (more predictably) lyrical narrative in the porter’s reminiscence of childhood.

UrbanArias gave an important piece the production values and cast it deserved, with an evocative square of park around a bench at the center of the black-box theater, and two singers who did a good job becoming three very different characters before our eyes. Jorell Williams, a plummy baritone, was particularly notable both for his liquid singing and his convincing incorporation of all three roles he played; the tenor Brandon D. Snook was slightly more keyed-up and self-consciously operatic, that is to say heightened in his emotion, playing three admittedly more keyed-up characters.

Opera doesn’t need to be obviously relevant to be important. But when one does take on a particularly topical subject, it’s nice to see it doing it justice. “Independence Eve” has some flaws, but it deserves to have a performance life.

Anne MidgetteAnne Midgette came to The Washington Post in 2008, when she consolidated her various cultural interests under the single title of chief classical music critic. She can be found online as The Classical Beat. Follow